Rock drill



GROSS Hummm mmm uuun Dec. 26, 1944. J. c. CUR-ns ROCK DRILL Filed Aug. 14, 1941 2 Sheets-Sheet l J.C.CURHS ROCK DRILL Dec. 26, 1944.

Filed Aug. 14, 1941 2 Sheets-Sheet 2 Patented Dec. 26, 1944 ROCK DRILL John C. Curtis, Claremont, N. H., assignor to Sullivan Machinery Company, a corporation of Massachusetts Application August 14, 1941, Serial No. 406,865

21 Claims.

This invention relates to rock drills, and more particularly to an improved drill steel centralizer for a hammer rock drill.

An object of the present invention is to provide an improved drill steel centralizer. Another object is to provide an improved drill steel centralizer having improved operating means whereby the centralizer may be readily moved into and out of its steel guiding position. A further object is to provide an improved drill steel centralizer having improved control means operable from a remote point. Yet another object is to provide an improved centralizer for the 4drill steel of a hammer rock drill of the shell guided drifter type, having improved control means operable from the rear end of the guide shell. A still further obiect is to provide an improved drill steel centralizer having improved means for moving the centralizer guide arms into and to hold the same in guiding position, together with means for automatically eilecting movement of the guide arms out of their guiding positions. A still further object is to provide improved guide arm operating means which is uid actuated and controllable from a remote point whereby the centralizer may be quickly released from the drill steel. Yet another object is to provide an improved drill steel centralizer which is provided with improved uid operated means for moving the centralizer guide arms into and out of their guiding position and for holding the guide arms in the guiding position. A further object is to provide improved means for automatically eifecting release of the guide arms of the centralizer when the drilling motor assumes a predetermined position with respect to the guide shell along which the drilling motor is guided. Another object isto provide an improved drill steel centralizer having a novel arrangement and combination of parts. With the above and other objects in view. this invention relates to novel features of construction. operation and arrangement of parts, examples of which are given in the specification and illustrated in the accompanying drawings, wherein:

Fig. 1 is a side elevational view of a hammer rock drill with which one form of the invention is associated, parts being shown in section to illustrate structural details.

Fig. 2 is an enlarged cross sectional view taken substantially on lone 2 2 of Fig. 1, showing the drill steel centralizer in its guiding position.

Fig. 3 is a view similar to Fig. 2, showing the centralizer in its released position.

Fig. 4 is a fragmentary jvievv, in longitudinal vertical section taken substantially on line 4 4 of Fig. 2.

Fig. 5 is an enlarged cross sectional view taken substantially on line 5 6 of Fig. 1, showing the 5 manual control valve.

Fis. 6 is an enlarged cross sectional view taken substantially on line 8 6 of Fig. 1, showing the automatic vent valve.

Fig. 7 is an enlarged detail sectional view of 10 ge rganual control valve taken on line 1 1 of Fig. 8 is an enlarged 'detail sectional view of ge xsnanual control valve taken on line I l of Fig. 9 is an enlarged horizontal sectional view taken through the guide shell substantially on line 8 9 of Fis. l.

Fig. 10 is an enlarged detail vertical sectional view of the automatic vent valve taken on line Ill-I0 of Fig. 9.

Fig. 1l is a view similar to Fig. 2, illustrating a modied form of drill steel centralizer.

Fig. 12 is a view similar to Fig. 11, showing the centralizer in its released position.

In both illustrative forms of the invention the improved drill steel centralizer, generally designated l, is associated with a conventional hammer rock drill of the mounted drifter type, generally designated 2. It will be evident, however.

that the centralizer may be associated with drills of other types if desired.

The rock drill 2 comprises a conventional drill hammer motor 3 slidably guided in the guideways 4, 4 of an elongated guide shell l, the latter having a usual bottom swivel plate i adapted to be clamped in a conventional drill support. Sup

ported, in a conventional manner, by tie rods and spacing sleeves at therear end of the guide shell is a cross yoke 1, and a feed screw t mounted on the guide shell is journaled at its rear end within this cross yoke and is journaled at its front end within a. frontl bearing support 9 attached to the front end of the shell, likewise by the tie rods. The feed screw has a usual manual operating handle l0 and engages a non-rotatable feed nut Il (Fig. 5) secured within a depending boss l2 integral with the motor cylinder Il of the hammer motor. 'I'he motor cylinder has longitudinal guides I4, I4 slidingly received in the shell guideways 4. 'I'he hammer motor has a front chuck housing I5 suitably attached t-'o the front end of the motor cylinder Il, and supported within a usual chuck mechanism carried within the chuck housing is the shank of ssausualdrillstecl Il. Asisusualinhammer drilling motors. the motor cylinder I3 contains a duid actuated hammer piston (not shown) for percussively actuating the drill steel. By rotating the feed screw 3. the hammer motor 3 may be fed back and forth along the shell guldeways.

The preferred form of the improved drill steel centraliser I. as shown in Figs. l to 10, inclusive, comprises a pair of cooperating guide arms I1, I1 pivotally mounted on parallel pivot bolts I8 secured to a bracket I3, herein preferably formed integral with the front bearing support s. 'l'hese guide arms are adapted to embrace the body of the drill steel I to hold the latter centered during spotting" or starting of a drill hole, in the manner well known to those skilled in the Secured to the bracket I3 below the guide shell is a cylinder 23 having a longitudinal bore 2I containing a fluid actuated piston 22. the latter having a piston rod 23 extending forwardly through a front cylinder head bushing 24. Encircling the piston rod and interposed between the bushing 24 and the piston head is a coil spring 25 which constantly urges the piston towards its rearmost position. The cylinder 20 and piston 22 cooperate to provide a servomotor. Formed on the forward portion ot the piston rod is a cam 2l of irusto-conical shape, and this cam engages the arcuate surfaces 21 of lever arms 23 herein formed integral with the centraliser guide arms. A bowed spring 2l pivotally connected at its ends at 2l' to the guide arms respectively and arranged between the guide arms, constantly urges'the guide arms toward their wide open position. W'hen the piston 22 is moved forwardly within the cylinder bore under the action of pressure iluld, the cam 23 is moved forwardly, thereby moving the lever arms 23 apart and swinging the centraliser guide arms into their guiding position, as shown in Fig. 2. When pressure iluid is supplied to the forward end of the cylinder bore and the reas' end of the cylinder bore is vented, the piston 22 is moved rearwardly, thereby releasing the cam from the lever arm surfaces 21 thus to permit the spring 2l to swing the guide arms apart into the position shown in Fig. 3. The pivot bolts I5 also serve to hold parts of the centraliser together, and, in this instance. they secure in position at the front side of the bracket I3 a plate 30 against which the piston rod 23 abuts when the piston 22 is in its foremost position. This plate also serves as a guard to protect certain of the centrallzer parts.

Manual control means is provided for ei'lecting actuation of the guide arms under the action of pressure fluid from a point remote from the centralizer near the rear end oi' the guide shell. Arranged in a transverse bore 3I in a depending boss integral with the guide shell is va rotary control valve 32 having an operating handle 33.1 This valve is hollow at 34 and its hollow interim' is connected to a suitable source of pressure fluid supply through a supply hose connection 35. ceiving Ibore 3l to a conduit 31 extending longitudinally along one side of the guide shell, as shown in Fig. 9, and connected by a passage 33 to a passage 35 ln the front ybracket Il. The passage 39, as shown in Fig. 4. communicates with the front end of the cylinder bore 2| at the front side of the piston. 'I'he valve 32, as shown in Fig. 7, has a port 43 for connecting the passage 35 with the hollow interior ot the valve, and a groove 4I on the valve is connectibie )l passage 35 connects the valve re.

34 to atmosphere, and as a result to vent the forward end of the cylinder borre 2l. As shown in Fig. 8, the valve 32 has a port 43 for connectlng the hollow interior of the valve to a passage 44 which is connected through s conduit 45 (Fig. 9) extending longitudinally along the opposite side ol the glulde shell. This conduit communicates with a passage 45 which in turn communicates with a vertical bore 41 formed in a boss 43 integral with the guide shell. Also communieating with the bore 41 is a passage 49 connected to a further conduit 5l which communicates with a e 5I, the latter in turn being connected by a passage 52 in the bracket I9 to the reauend of the cylinder ybore at the rear side ol the piston. Contained in the bore 41 is a vertically reciprocable plunger valve 53, and interposed between a plug 54 closing the lower end of the valve-recelving-bore and the lower surface of the plunger valve is a coil spring 55 which constantly urges the plunger valve toward its uppermost position. The plug 54has a vent port 55, and the plunger valve has an angular passage 51 tor connecting the e 45 to this vent port when the plunger valve is in its lowered position. as shown in Fig. 10. Extending about the periphery of the valve is an annular groove 53 for connecting the passages 46 and 4s together when the plunger valve is in its released position. The plunger valve has a valve stem 53 projecting u-pwardly into one of the shell guidewavs 4, and one of the cylinder guides I4 is elongated at III and farmed with a sloping surface, and when this guide-elongation engages the valve stem the plunger valve is depressed against the action of the coil spring 55. Any suitable means, not shown, as for example a longitudinal groove on the stem 59 into which a stationary pin or the like projects, may be used to prevent rotation of the valve 53 to a position which would defeat the intended mode of operation. It is accordingly evident that as the drill hammer motor is I fed forwardly along the gideways of the guide shell, the elongation 50 of the cylinder guide engages the valve stem 53 at a predetermined point in the feeding travel of the drill hammer motor. and as a result the plunger valve is depressed to move the passage 51 to connect the passage 44 to the vent port 55, thereby to vent the rear end of the cylinder bore 2I to atmosphere to permit the coil spring 25 to move the piston 22 rearwardly. When the piston 22 is moved into its rearmost position in its cylinder bore, the cam 26 is released from the lever arms 23 and as a result the centralizer guide arms are swung outwardly into their non-guiding posltion -by the spring 29. Thus engagement of the iront end of the chuck housing of the hammer motor with the centraliser guide arms is impossible. A groove 5I (Fig. 8) is communicable with a vent passage 52 for connecting the passage 44 to atmosphere thereby to exhaust the nuld from the rear Iend of the cylinder bore 2I when the plunger valve 53 is in its raised nonventing position Thus under the control of the rotary valve 32, the guide arms may be moved at.

will into guiding or non-guiding positions from the operators station at the rear end of the guide shell. The stem 53 may be made a loose enough ilt in its receiving bore or any suitable vent passage directly to prevent accumulation of pressure duef to leakage acting in an undesired manner on 'the top of the valve 53.

In the modinediorm of the invention shown in to a vent port `42, thereby to vent the passage 1s Figs. l1 and 12 there is formed integral with the bracket I9 a depending cylinder 6l having its bore e9 vertically disposed and containing a vertically reciprocable piston 81. This piston has its piston rod 68 projecting upwardly through .the top cylinder head 69 and secured to a block 10. This block is pivotally connected at 'Il to links or arms 'I2 which are in turn respectively pivotally connected at 13 to the centralizer guide arms. Interposed between the bottom of the cylinder and the piston is a coil spring M which constantly urges the piston toward its uppermost raised position. In this construction, the passage 39 in the bracket I9 is connected to the lower end of the cylinder bore B8 while the passage 52 in the bracket is connected to the upper end of the cylinder bore and the above described nuid conducting passages 39, 4l in the guide shell are connected to these passages 39 and 52 in the manner above described, and when pressure uid is supplied to the upper end of the cylinder bore 68 under the control of the rotary valve 32, the piston 61 is moved downwardly, thereby to swing the centralizer guide arms into their guiding position as shown in Fig. l1. When pressure uid is supplied to the lower end of the cylinder bore beneath the piston 81 and the upper end of the cylinder bore is vented to atmosphere, the piston 51 is moved upwardly into the position shown in Fig. l2 to swing the guide arms into their wide open non-guiding position. As in the other form of the invention. when the cylinder guide elongation 80 engages the stem 59 of the plunger valve 53, the upper end of the cylinder bore is vented to atmosphere,V

thereby causing the coil spring 1| to move the piston 51 into its position shown in Fig. 12. As a result the centralizer guide arms are swung into their non-guiding position before engagement of theforward end oi the chuck housing with the guide arms can occur. Otherwise this form oi' the invention is similar to that above described.

In both forms of the invention the automatic control valve may effect control of the ilow of fluid to the ends of the centralizer cylinder and the spring acting on the piston may be omitted. With such arrangement the automatic valve would effect venting of one end of the cylinder and supply to the opposite end. so that the centralizer would be moved to non-guiding position under the actuation of pressure uid. Thus the guide arms would be thrown open solely by pressure iluid without the aid of a spring.

As a result of this invention it will be noted that an improved drill steel centralizer is provided having novel control means whereby movement of the centralizer guide arms into and out of their guiding positions may be e'ected from a remote point. Such arrangement is particularly desirable since the operator can eiect release oi' the centralizer from the drill steel from his station at the rear end of the guide shell. Also by the provision of the duid-actuated operating means for the centralizer guide arms, the centralizer may be easily and quickly moved into and held in its guiding position, or released from the drill steel. Further by the provision of the au-4 tomatic vent valve for controlling the centralizer operating piston any possibility of the drill hammer motor striking against the centralizer arms is precluded. Other uses and advantages of the improved drill steel centralizer will be clearly apparent to those skilled in the art.

While there are in this application speciiically described two forms which the invention may assume in practice, it will be understood that these forms of the same are shown for purposes oi illustration and that the invention may be modiiied and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

l. A centralizer for drill steels comprising a support, a guide element mounted on said support for movement with respect thereto into and out oi' its steel guiding position, and power operated means carried by said supportand stationary as regards bodily movement longitudinally with respect thereto, said power operated means being operatively connected to said guide element for moving the latter from one of its positions to the other.

2. A centralizer for drill steels comprising a support, a guide element mounted on said support for movement with respect thereto into and out of its guiding position, and power operated means carried by said support for moving said guide element into its guiding position and and for holding the same in such position.

3. A centralizer for drill steels comprising a support. guiding means mounted on said support to move with respect thereto from guiding to non-guiding position, and iluid actuated means on said support for moving said guiding means from one position to the other.

4. A centralizer for drill steels comprising a support, guiding means mounted on said support to move with respect thereto from guiding to non-guiding position, and iluid actuated means on said support for moving said guiding means from its non-guiding position to its guiding positgin and for holding the same in said latter pos on.

5. A centralizer for drill steels comprising a support, a pair oi' cooperating relatively movable guide arms pivotally mounted on said support to swing toward and from guiding relation with a drill steel, uid actuated means for swinging said guide arms about their pivots into steel guiding position and for holding said arms in steel guiding position, and means for automatically swinging said guide arms into non-guiding position when said holding means is released.

6. A centralizer for drill steels comprising a support, guiding means on said support movable into and out of steel guiding position, power operated means on said support and stationary as regards bodily movement longitudinally with respect thereto, said power operated means engaging said guiding means for holding the latter in steel guiding position and including a power operated holding element movable relative to said support into and out of holding relation with respect to said guiding means, means operable at will for eil'ecting movement of said holding ele ment of said holding means out oi' its holding position, and means for automatically positively moving said guiding means into its non-guiding position when said holding means is released. l 7. In a drill steel centralizer, a support, guide arms pivotally mounted on said support and swingable about their pivots between guiding and non-guiding positions, a cylinder carried by said support, and a iiuid actuated piston contained in said cylinder and operatively connected to said guide arms for effecting swinging of the latter about their pivots.

8. In a drill steel centralizer, a support, a pair of cooperating guides pivoted on said support, a iiuid actuated piston for swinging said guides about their pivots into guiding position. and resilient means for swinging said guides about their pivots into non-guiding position when the pressure uid acting on said piston is vented.

9. In a drill steel centralizer, a support, a pair of cooperating guides pivoted on said support, and a duid actuated piston on said support for swinging said guides about their pivots into and out oi guiding position.

10. In a drill steel centralizer, guiding. means movable into and out oi guiding position, fluid actuated means for moving said guiding means from one position to the other, and valve means for controlling iluid ilow to said iluid actuated means.

11. In a drill steel centralizer, guiding means movable into and out of guiding position, fluid actuated means for moving said guiding means from one position to the other. and valve means located at a point remote from said 'guiding means for controlling iluid now to said nuid actuated means.

12. In combination, a guide, a drill steel actuator guided on said guide, a drill steel centralizer arranged at the front end of said guide, power operated means for operating said centralizer, and automatic means operable when said drill steel actuator is in a predetermined position with respect to said guide for controlling said power operated means to cause said centralizer to move out of its guiding position, thereby to preclude engagement of the drill steel actuator with the centralizer.

13. In combination, a guide, a. drill steel actuator guided on said guide, a drill steel centralizer at the front end of said guide, means for constantly urging said centralizer out or its guiding position, means for holding said centralizer in its guiding position against the action of said constantly-urging means, and automatic means operable when said drill steel actuator is in a predetermined position with respect to said guide and while said drill steel actuator is still spaced from said centralizer for releasing said holding means to cause said constantly-urging means to move said centralizer out of its guiding position, thereby to preclude engagement of the drill steel actuator with the centralizer.

14. A drill steel centralizer comprising a support, guiding elements mounted on said support for movement into and out of their guiding positions, and a fluid actuated element for retaining said guiding elements in their guiding position.

15. In combination, a guide, a drill steel actuator guided on said guide, a drill steel centralizer at the front end of said guide, means for constantly urging said centralizer out of its guiding position, means for holding said centralizer in its guiding position against the action of said constantly urging means, and means respectively controlled by the movement of said drill steel actuator upon said guide and operative at will while said drill steel actuator is stationary, for rendering said holding means inoperative.

16. In combination, a guide, a drill'steel actuator guided on said guide, a drill steel centralizer at the front end of said guide, means for constantly urging said centralizer out of its guiding position, means for holding said centralizer in its guiding position against the action of said constantly urging means, and means respectively operative automatically when said drill steel actuator is adjacent the forward end of said guide and operative at will when said drill steel actuator is in any position to the rear of said forward position in which automatic control of said holding means takes place, for rendering said holding means inoperative.

17. A. centralizer for drill steels comprising a support. guiding means on said support movable into and out of guiding position with respect to a drill steel, a servo-motor embodying a movable power actuated element operatively connected to said guiding means for moving the latter in one direction from one of its positions to the other, means operable at will for controlling the operation of said servo-motor, and means for automatically moving said guiding means in the opposite direction when said servo-motor is inoperative.

18. A centralizer i'or drill steels comprising a guide element movable into and out of its guiding relation with respect to a-drill steel, a servomotor embodying a movable power actuated element operatively connected to said guide element for moving the latter from one position to the other, and means operable at will for controlling the operation oi' said servo-motor.

19. A centraliser for drill steels comprising a support, a pair oi cooperating relatively movable guide arms pivoted on said support to swing into and out of guiding relation with a drill steel, and means operatively connected to said arms i'or swinging said arms selectively in opposite directions about their pivots toward and from the drill steel, said arms-swinging means including iluid actuated means for eilecting the swinging of said arms in one of said opposite directions.

20. A centralizer for drill steels comprising a support, a pair of cooperating relatively movable guide arms pivoted on said support to swing into and out of guiding relation with a drill steel, means carried by said support for swinging said arms inwardly toward the drill steel and for holding said arms in steel guiding position, and means for automatically swinging said guide arms outwardly relative to the drill steel into nonguiding position when they are released from such holding. said first mentioned means including iluid actuated means and being eil'ective to swing said arms inwardly into and to hold the same in steel guiding position against the action of said automatic swinging means.

21. A centralizer for drill steels comprising a support, a pair of cooperating relatively movable guide arms pivoted on said support to swing into and out of guiding relation with a drill steel, and iluid actuated means operatively connected` to said arms for swinging said arms from their nonguiding position inwardly about their pivots into guiding relation with the drill steel and for holding said arms in guiding position.

JOHN C. CURTIS. 

